CONN 
S 
43 
.E22 

no.108 


Digitized  by  the  Internet  Archive 

in  2011  with  funding  from 

LYRASIS  members  and  Sloan  Foundation 


http://www.archive.org/details/examinationofseeOOnewh 


7 -Ad  8  .&'  I  OS 


1 


O.  E.  S.  I  -BRARY.  Cop.  a. 


Co 

s 

Hi 
.E< 


THE 


Connecticut  Agricultural  Experiment  Station, 

NEW    HAVEN,    (JaifcfeFlmMit  BtriltfHft. 

Hsc'd • 

Ani.d....Moaafl.. 


BULLETIN     No.     108. 


MAY,  1891. 


The  Bulletins  and  Reports  of  this  Station   are  mailed  free  to 
every  citizen  of  Connecticut  who  applies  for  them  seasonably. 


CO^TEITS. 

1.  Examination  of  the  Seed  of  Orchard  Grass,  .  .  .2 

2.  Ash  Analysis  of  White  Globe  Onions,  ....        4 

3.  On  the  Determination  of  Fat  in  Cream  by  the  Babcock  Method,        5 


The  matter  of  this  Bulletin,  that  has  any  permanent  value,  will  be 
carefully  revised  and  made  part  of  the  next  Annual  Report  of  the 
Director  of  this  Station. 


EXAMINATION  OF   THE  SEED  OF  ORCHARD  GRASS, 

Dactylis  glomerata. 

This  species  is  one  of  the  best  meadow  grasses.  It  roots 
deeply  and  is  less  affected  by  drought  than  most  other  grasses, 
it  grows  better  in  the  shade  than  timothy  or  red-top  and  is 
earlier  in  bloom,  it  is  believed  to  be  more  permanent  than 
timothy  on  land  suited  to  it  and  gives  large  crops.  If  cut  before 
full  bloom  the  hay  is  nutritious  and  not  coarser  or  more  strawy 
than  timothy. 

But  little  orchard  grass  is  grown  in  this  State.  Many  who 
have  tried  it  have  either  failed  to  get  a  good  catch  or  have  got 
a  catch  altogether  too  good  of  grasses'  other  than  orchard 
grass,  notably  of  meadow  fescue,  JFestuca  pratensis,  perennial 
rye  grass,  Lolium  perenne, — perennial  only  in  name — and  chess 
or  cheat,  JBromus  secalimis.  This  fescue  is  a  good  meadow 
grass,  but  rye-grass  and  chess  are  very  inferior  or  worthless. 

The  failures  made  in  sowing  orchard  grass  and  the  consequent 
indifference  to  it  are  largely  to  be  explained  by  the  quality  of 
seed  which  is  offered  in  market.  To  learn  the  present  state  of 
the  trade,  this  Station  has  recently  examined  six  samples  of  seed 
bought  by  farmers  of  seedsmen  in  the  State,  six  samples  pur- 
chased in  Boston  and  five  in  New  York.  The  results  of  the 
botanical  analyses  and  germination  tests  are  given  in  the  fol- 
lowing table.  The  per  cents  of  different  seeds  found  in  the 
samples  are  by  weight  and  not  by  number.  No  attempt  was 
made  to  identify  other  seeds  than  those  named  in  the  table. 
Many  seeds  were  immature  and  the  duplicate  sprouting  tests  did 
not  in  some  cases  agree  closely,  but  that  the  conditions  of  the  tests 
were  suitable  is  shown  by  the  fact  that  good  mature  seed  sprouted 
freely  in  the  testing  apparatus.  Four  tests  were  made  of  each 
of  the  samples  from  A  to  G  and  two  tests  of  each  of  the 
others.  The  highest  result  in  each  case  is  given  in  the  table. 
The  last  column  of  the  table  is  prepared  by  multiplying  the 
per  cent,  of  pure  orchard  grass  seed  by  the  per  cent,  of  this  pure 
seed  that  is  capable  of  sprouting  and  dividing  the  product  by  100. 


The  results  of  this  examination  may  be  summarized  as  follows: 

1.  Of  the  17  samples  of  Orchard  grass  seed  purchased  in  New  York, 
Boston,  and  at  various  places  in  Connecticut,  one  sample  contained 
as  much  as  98.8  per  cent,  of  pure  seed  the  remainder  being  chaff. 
Another  contained  no  orchard  grass  seed  whatever,  and  consisted 
mainly  of  Lolium  perenne,  or  perennial  rye-grass. 

Excluding  this  sample  the  other  16  samples  contained  on  the  average 
77.4  per  cent,  of  pure  seed. 

2.  Seven  out  of  sixteen  samples  contained  notable  quantities,  from  8.3 
to  35-5  Per  cent.,  of  seed  of  perennial  rye-grass,  Lolium  perenne,  which 
is  less  valuable  and  sells  at  a  lower  price.  "  Tested "  Orchard  grass 
seed  is  quoted  at  11  cents  per  pound  and  "tested  "  perennial  rye  grass 
at  4A  cents.  A  single  sample  contained  14. 1  per  cent,  of  a  species  of 
Bromus,  probably  secalinus  or  chess. 

3.  In  one  sample  as  high  as  88  per  cent,  of  the  orchard  grass  seed 
sprouted,  in  another  as  low  as  4.5  per  cent,  and  on  the  average  of  16 
samples  50.0  per  cent. 

4.  Taking  the  16  samples  together,  the  average  quantity  of  pure 
orchard  grass  seed  which  was  capable  of  sprouting  was  40  per  cent.;  i.  e. 
out  of  every  100  pounds  bought,  40  pounds  was  pure,  live  seed. 
Probably  the  quantity  that  would  produce  healthy  plants  was  less  than 
this. 

EXAMINATION    OF    ORCHARD    GRASS    SEED    FROM 

THE   CONNECTICUT,   BOSTON,   AND   NEW 

YORK  MARKETS. 


Botanical  Analysis. 

SO 

Sprouting  Test. 

1 

to 

2 

~ 

Mark. 

c3 

I 

0 

p 
p. 

■3 
3 

J3 

0 

a 
a 

s 

1 

02:3 
S"2 

m  OS 

O  60 

cent. 
ed    i 
e  cai 
routi 

0 

j=g. 

F-<  a 

!-,  Mr;  a 

a; 

CJ'^H 

0  tn  p,a> 

O 

s 

Bh 

cq 

0 

s 

Cn 

(^ 

A 

58.6 

20.5 

20.9 

.666 

41.0 

24.0 

B 

69.6 



14.1 

16.3 

.571 

27.5 

19.1 

C 

76.1 

2.5 

8.3 



13.1 

.773 

43.0 

32.7 

D 

67.2 

4.7 

8.9 

19.2 

.537 

32.5 

21.8 

F 

94.7 





5.3 

.621 

40.5 

38.4 

G 

43.9 



23.1 



33.0 

.535 

36.0 

15.8 

I 

92.9 





7.1 

.729 

54.5 

50.6 

J 

87.8    . 



■ 



12.2 

.495 

42.5 

3T.3 

K 

60.3 







29.7 

.588 

44.0 

26.5 

L 

88.2 







11.8 

.838 

79.0 

69.7 

M 

none. 













none 

N 

65.7 

31.4 



2.9 

.609 

4.5 

3.0 

0 

98.8 



--.. 



1.2 

.902 

35.0 

34.6 

P 

92.0 



8.0 

.555 

88.0 

81.0 

Q 

97.7 







2.3 

.740 

76.5 

74.7 

R 

81.6 

15.7 



2.7 

.745 

77.0 

62.8 

S 

62.7 



35.5 



1.8 

.779 

82.5 

51.7 

It  is  very  likely  that  rye  grass  is  sometimes  added  as  a  "  make- 
weight," and  it  may  easily  escape  detection  in  a  casual  examina- 
tion, but  it  often  grows  with  orchard  grass,  and  when  the  two 
kinds  of  seeds  are  harvested  together  it  is  impossible  by  me- 
chanical means  to  separate  them. 

Moreover,  the  trade  seed  of  orchard  grass  even  when  pure  is 
known  to  have  a  low  germinating  power  both  abroad  and  in  this 
country,  so  that  30  to  35  pounds  per  acre  of  it  make  only  mod- 
erate seeding. 

The  table  of  analyses  shows  however  that  it  is  still  possible, 
if  one  will  take  pains  enough  and  pay  enough,  to  get  quite  clean 
seed  of  this  grass  of  which  over  60  per  cent,  will  germinate. 

A  part  of  the  trouble  with  the  seed  market  is  that  while  the 
best  seed  is  naturally  the  most  expensive,  cheap  seed  is  always 
the  most  popular. 

The  sample  P  represents  seed  for  which  there  is  absolutely  no 
market  in  its  pure  state  ;  it  is  too  good  for  the  trade  and  is  mixed 
again  for  sale  with  inferior  and  less  "  expensive  "  seed. 

It  is  obvious  however  that  as  compared  with  sample  A,  sample 
P  is  by  far  the  more  economical.  In  the  first  place  a  pound  of  P 
will  produce  more  than  three  times  as  many  plants  of  orchard 
grass  as  A.  Again  A  will  seed  the  land  with  some  rye  grass 
which  is  quite  inferior  to  orchard  grass.  And  lastly  the  catch  of 
grass  from  the  A  seed  will  probably  be  poor,  and  very  likely  so 
poor  that  the  land  will  have  to  be  re-seeded.  In  this  case  it  may 
lie  idle  for  six  months  or  a  year  and  confirm  the  owner  in  the  idea, 
that  orchard  grass  is  not  worth  a  trial. 

To  any  one  in  the  State  desiring  them,  a  few  seeds  each  of 
Orchard  grass,  Perennial  rye  grass  and  Meadow  Fescue  will  be 
sent  by  the  Station  to  aid  in  their  identification. 


Ash  Analysis  of  White  Globe  Onions. 

From  several  barrels  of  White  Globe  Onions  grown  at  Green's 
Farms  were  selected  twenty-two  bulbs  of  fair  size  which  weighed 
five  pounds  and  one  ounce. 

After  drying  and  pulverizing  them,  a  weighed  sample  of  the 
powdered  material  was  burned  with  the  usual  precautions  and 
the  ash  submitted  to  analysis  with  the  following  results  : 


Per  cent.   Composition  of  the  Pure  Ash. 
[Station  No.  3005.] 

Potash 43.49 

Soda .-     1.26 

Lime 1 0.87 

Magnesia 4.46 

Oxide  of  iron 1.07 

Phosphoric  Acid 19.08 

Sulphuric  Acid 15.98 

Chlorine 2.36 

Sand  and  Silica 1.96 

100.53 
Deduct  oxygen  equivalent  to  chlorine .53 

100.00 

The  fresh  onions  contain  .27  per  cent,  of  nitrogen  and  .48  per 
cent,  of  pure  ash. 

From  these  data  are  calculated  the  quantities  of  these  ingre- 
dients contained  in  one  ton,  2000  pounds  of  onions  as  follows  : 

Nitrogen  and  Mineral  Matter  in  One  Ton  of  Onions  (Bulbs), 

Nitrogen  _ 2.70  pounds. 

Phosphoric  Acid .92 

Potash 2.09 

Soda .06 

Lime. .....     .52 

Magnesia .21 

Oxide  of  Iron .05 

Sulphuric  Acid .77 

Chlorine .11 

Sand  and  Silica : .09 


ON  THE  DETERMINATION  OF  FAT  IN  CREAM  BY 
THE  BABCOCK  METHOD. 

In  his  paper  describing  this  method,  Wis.  Ex.  St.  Rep.  1890, 
110,  Dr.  Babcock  speaks  as  follows  of  the  determination  of  fat 
in  cream. 

"The  chief  difficulty  in  testing  cream  lies  in  the  sampling.  Cream 
that  is  sour,  or  that  has  been  exposed  to  air  until  the  surface  has  dried 
cannot  be  accurately  sampled.  The  same  is  true  of  centrifugal  cream 
that  is  badly  frothed.     Sweet  cream,  from  Cooley  cans,  that  is  not  too 


6 

thick  to  flow  readily  from  the  pipette  can  be  tested  with  satisfactory 
results.  The  process,  however,  must  be  modified  slightly  from  that 
used  with  milk,  as  the  amount  of  fat  in  cream  is  so  large  that  it  cannot 
be  measured  in  the  ordinary  test  bottles  if  the  usual  quantity  is  taken 
for  the  test,  and  besides  a  much  greater  error  results  from  the  cream 
which  adheres  to  the  pipette  than  with  milk.  Both  of  these  difficulties 
may  be  overcome  by  taking  two  or  three  test  bottles  and  dividing  the 
test  sample  into  as  nearly  equal  portions  as  can  be  judged  by  the  eye. 
The  pipette  is  then  filled  with  water  and  this  is  run  into  the  tubes  in 
the  same  way  as  the  cream.  If  three  bottles  are  taken  the  pipette  is 
filled  with  water  a  second  time  and  emptied  into  the  bottles  as  before. 
This  serves  to  rinse  the  cream  from  the  pipette,  and  at  the  same  time 
to  dilute  it  to  a  point  where  it  can  be  tested  in  the  same  way  as  milk. 
The  bottles  are  then  treated  in  the  usual  manner,  and  the  reading  of 
the  tubes  added  together  for  the  per  cent,  of  fat  in  the  cream. 

Owing  to  the  low  specific  gravity  of  cream,  the  test  sample,  if  of  the 
same  volume,  will  weigh  less  than  that  of  milk,  and  consequently  the 
per  cent,  of  fat  as  shown  by  the  scale  will  be  less  than  is  found  by 
gravimetric  analysis,  in  proportion  as  the  weight  is  less  than  18  gms. 
Where  a  delicate  balance  is  available,  this  error  may  be  entirely  avoided 
by  weighing  the  cream  used  in  the  test,  and  calculating  the  per  cent, 
of  fat  by  multiplying  the  scale  reading  by  *£-,  a,  being  the  weight  of 
cream  taken. 

If  17.6  c.  c.  of  cream  is  taken  and  the  portion  adhering  to  the  pipette 
is  rinsed  into  the  test  bottle,  a  close  approximation  of  the  true  result 
may  be  obtained  without  weighing  by  correcting  the  scale  reading  as 
follows  :  For  a  scale  reading  of  20  per  cent.,  add  .25  per  cent.  ;  for  a 
scale  reading  of  15  per  cent.,  add  0.1  per  cent.  Readings  between  these 
may  be  corrected  in  proportion.  Below  10  per  cent,  no  correction  is 
necessary." 


Most  of  the  creameries  in  this  State  gather  cream  rather  than 
milk  and  the  cream  is  usually  raised  by  deep  setting  in  submerged 
cans  at  low  temperatures.  A  rapid  and  accurate  method  of 
determining  fat  in  cream  which  can  be  used  in  creameries,  is 
therefore  particularly  desirable  here. 

The  Babcock  method  has  been  thoroughly  tested  in  the  last 
few  months  by  Mr.  Winton,  chemist  of  the  Station,  with  a  view 
to  its  use  by  cream  gathering  creameries. 

The  same  apparatus,  bottles,  acid  and  method  have  been 
employed  as  are  recommended  by  Dr.  Babcock  and  referred  to 
in  Bulletin  106  of  this  Station,  with  a  single  exception.  For 
creamery  use  it  is  absolutely  essential  that  all  weighing  should 
be  dispensed  with  and  that  the  cream  should  be  measured  and 
not  weighed  for  individual  tests.     The  use  of  three  test  bottles  for 


a  single  sample  of  cream  adds  greatly  to  the  labor  when  many 
samples  require  to  be  tested.  The  correction  to  be  made  to  the 
reading  of  the  tubes  also  on  account  of  the  specific  gravity  of 
the  cream  adds  somewhat  to  the  care,  skill  and  time  required. 

Mr.  Winton  has  therefore  made  and  used  in  all  the  tests  given 
below  a  pipette  for  measuring  the  cream  which  delivers  6  grams 
of  cream  quite  accurately,  provided  the  cream  was  raised  as  above 
described.  The  reading  from  the  tube  multiplied  by  three  gives 
the  per  cent,  of  fat  in  the  cream  without  further  correction. 

The  pipette. — The  pipette,  made  by  Mr.  Winton,  is  6^  inches 
long,  narrow  at  each  end,  the  internal  diameter  at  one  end  being 
about  ^  of  an  inch  and  at  the  other  ^  inch. 

It  is  designed  to  deliver  6  grams  of  cream,  as  the  milk  pipette 
is  designed  to  deliver  18  grams  of  milk.  The  actual  quantity 
delivered  in  several  preliminary  trials  was  5.97-5.95-6.00  and 
5.93  grams. 

The  number  of  grams  of  water  delivered  (15°  C.)  by  this  pipette 
in  a  number  of  trials  was 

6.035 

6.038 

6.028 

6.053 

6.045 

6.035 


Average  6.039 

The  volume  of  cream  delivered  will  be  less  than  that  of  water 
because  a  larger  proportion  of  the  cream  will  adhere  to  the  sides 
of  the  pipette. 

Method  of  using  the  pipette. — The  cream  is  very  thoroughly 
mixed  by  moderate  agitation, — violent  shaking  may  churn  it  par- 
tially or  beat  it  full  of  small  bubbles  which  are  very  slow  to  rise, 
— and  the  pipette  with  one  end  well  below  the  surface  of  the 
cream  is  sucked  full,  a  little  escaping  into  the  mouth.  The  upper 
end  is  closed  with  tbe  tongue,  and  the  pipette  withdrawn,  its  tip 
introduced  into  the  neck  of  the  flask  and  on  removing  the  tongue 
the  cream  flows  out.  As  soon  as  it  has  run  out,  the  adhering 
drop  is  blown  out  and  the  pipette  withdrawn. 

The  reason  for  making  the  pipette  to  be  completely  filled  with 
cream  rather  than  to  be  filled  to  a  mark  on  its  stem  is  that  it  is 
much  more  difficult  to  observe  in  a  tube  the  height  of  cream  than 


of  milk,  the  sides  of  the  tube  above  the  cream  level  being  coated 
with  cream  and  nearly  opaque  in  consequence.  By  filling  the 
tube  full  moreover,  any  bubbles  on  the  cream  surface  will  be 
removed  by  the  mouth. 

Having  measured  the  cream  into  the  testing  flasks  it  is  only 
necessary  to  add  to  each,  12  centimeters  of  water,  from  a  pipette 
made  for  the  purpose,  and  then  proceed  exactly  as  in  the  case  of 
milk  only  multiplying  the  per  cent,  of  fat,  as  read  from  the 
graduations,  by  three. 

Following  is  a  complete  account  of  the  experiments  thus  far 
made  with  this  method,  with  the  exception  of  the  first  ten  samples 
examined  which  were  quite  sour  when  tested  and  had  not  been 
raised  by  a  uniform  method. 

The  "  gravimetric  method  "  referred  to  below  or  the  laboratory 
analytical  method,  which  is  the  standard,  consisted  in  weighing 
the  cream  accurately  on  asbestus  fiber  in  a  tube,  drying  at  the 
heat  of  boiling  water  till  the  weight  was  constant,  and  then 
extracting  the  fat  completely  from  the  tube  and  asbestus  with 
absolute,  alcohol-free  ether,  evaporating  the  ether,  drying  at  the 
temperature  of  boiling  water  and  weighing  the  residual  fat. 


Creamery  No. 
Collected  Feb.  10th, 

Solids. 
1891. 

Fat. 
Babcock  Method.     Gi 

•avimetric  Method. 

Babcock  method 
gave  more  (+)  or 
less  (— )  than  Grav- 
imetric Method. 

3 



21.3 

21.16 

+ 

.14 

6 



21.6 

21.30 

+ 

.30 

9 



18.9 

18.64 

+ 

.26 

11 



18.2 

17.90 

+ 

.30 

19 



20.25 

20.34 

+ 

.09 

21 



20.4 

20.36 

+ 

.04 

22 



17.7 

17.76 

— 

.06 

23 

20.25 

20.17 

+ 

.08 

25 



18.45 

18.67 

— 

.22 

29 



20.55 

20.57 

— 

.02 

30 



22.5 

22.90 

- 

.40 

Collected  Feb.  20: 

1891. 

2 

27.40 

20.4 

20.16 

+ 

.24 

3 

30.14 

22.7 

22.51 

+ 

.19 

4 

25.69 

18.6 

18.49 

+ 

.11 

5 

27.87 

21.0 

20.80 

+ 

.20 

6 

27.40 

21.9 

22.09 

— 

.19 

7 

27.52- 

19.8 

19.66 

+ 

.14 

8 

25.50 

18.0 

17.72 

+ 

.28 

9 

28.36 

21.0 

21.02 

— 

.02 

11 

31.18 

23.9 

23.54 

+ 

.36 

Babcock  method 

Creamery  No. 
Collected  Feb.  10th 

Solids. 
,  1891. 

Fat. 
Babcock  Method.       Gi 

gave  more  (+)  or 

less  (-)  than  Grav- 

•avimetric  Method,    imetrlc  Method. 

12 

27.77 

20.5 

20.64 

-  .14 

13 

26.15 

19.0 

18.96 

+  .04 

14 

28.70 

21.9 

21.24 

-  .04 

15 

26.38 

19.9 

19.64 

+  .26 

16 

26.46 

20.1 

19.79 

+  .31 

17 

26.91 

19.8 

19.66 

+  .14 

18 

26.57 

19.5 

19.15 

+  .35 

19 

27.45 

20.4 

20.23 

+  .17 

20 

27.13 

20.4 

20.58 

-  .18 

Collected  March  27,  1891. 

1 

j  19.8 
I  19.8 

20.14 



—  .34 

2 

{  20.7 
(  20.7 

20.98 



20.99 

-  .28 

j  21.0 
(  21.3 

21.37 

3 



21.39 

-  .22 

4 

(  19.2 
(  19.5 

19.76 



19.66 

-  .36 

5 

(  20.7 
1  20.4 

20.27 



20.45 

+  .19 

6 

---- 

j  22.8 
(  23.1 

22.66 
23.08 

+  .08 

7 

---- 

(  21.0 
i  21.0 

20.94 
21.00 

+  .03 

8 

---- 

j  18.3 
1  18.3 

18.25 
18.26 

+  .04 

9 

.... 

j  18.3 
1  18.3 
i  20.4 
j  20.4 

18.21 
18.46 
20.57 

-  .03 

10 



20.58 

-  .17 

Collected 

April 

23d,  1891. 

1 

27.15 

i  20.4 
•1  20.7 

20.51 

+  .04 

4 

26.77 

j  20.1 
\  20.4 

20.35 

-  .10 

5 

26.74 

20.7 

20.74 

—  .04 

6 

27.67 

22.2 

22.26 

—  .04 

7 

29.71 

j  23.4 
\  23.4 

23.81 

—  .41 

8 

28.53 

S  21.3 
(  21.6 

21.60 

-  .15 

9 

26.48 

19.8 

20.36 

-  .56 

10 

28.78 

21.9 

22.16 

-  .26 

11 

27.91 

j  20.7 
(  20.1 

20.42 

—  .02 

13 

27.42 

21.0 

20.80 

+  .20 

14 

27.77 

21.0 

20.97 

+  .03 

10 

Results. — The  average  quantity  of  fat  as  determined  in  the 
fifty  tests  above  given,  by  the  Babcock  method  was  20*46  per 
cent,  and  by  the  gravimetric  or  standard  method  was  the  same, 
20.46  per  cent. 

In  26  cases  the  former  gave  a  higher  result  than  the  latter,  in 
24  cases  the  reverse  was  the  case. 

In  18  cases  the  variation  of  the  two  methods  was  a  tenth  of 
one  per  cent,  or  less  ;  in  35  cases  the  variation  was  less  than  a 
quarter  of  one  per  cent.  In  1  cases  the  difference  exceeded  a 
third  of  one  per  cent,  and  the  extreme  difference  was  .56  per 
cent.     The  same  facts  may  be  expressed  as  follows  : 

In  36  per  cent,  of  the  tests  the  variation  from  the  standard 
method  was  not  more  than  one-tenth  of  a  per  cent. 

In  70  per  cent,  of  the  tests  the  variation  from  the  standard 
method  was  not  more  than  a  quarter  of  a  per  cent. 

In  86  per  cent,  of  the  tests  the  variation  from  the  standard 
method  was  not  more  than  a  third  of  a  per  cent. 

In  98  per  cent,  of  the  tests  the  variation  from  the  standard 
method  was  not  more  than  a  half  of  a  per  cent. 

In  considering  these  figures  and  the  accuracy  of  the  method  it 
must  be  borne  in  mind  that  the  per  cent,  of  fat  is  from  four  to 
six  times  as  great  in  cream  as  in  milk  and  hence  a  larger  dif- 
ference in  the  percentage  of  fat  found  in  cream  by  the  two 
methods,  may  not  involve  any  larger  proportion  of  the  total 
quantity  of  butter  fat  than  a  much  smaller  difference  in  the  per 
cent,  of  fat  found  in  milk  by  the  two  methods  involves  in  the 
total  quantity  of  the  fat  of  milk. 

To  illustrate.  If  a  sample  of  milk  contains  4  per  cent,  of  fat 
and  the  Babcock  method  shows  3.92,  the  agreement  is  all  that 
could  be  desired.  The  per  cent,  difference  is  only  .08.  That  is 
out  of  4  pounds  of  fat  .08  of  a  pound  or  2  per  cent,  is  missing. 
Now  if  a  sample  of  cream  contains  20  per  cent,  of  fat  and  the 
Babcock  method  shows  19.60,  the  per  cent,  difference  is  .40  which 
is  five  times  as  large  as  in  the  case  of  milk.  Yet  proportionally 
no  more  fat  is  lost  than  in  milk,  i.  e.  two  per  cent. 

In  more  than  four-fifths  of  the  cases  above  cited  the  error  is 
considerably  less  than  this. 


11 

The  results  above  given  lead  us  to  believe  that  the  Babcock  method 
may  be  made  of  very  great  value  to  cream-gathering  creameries.  It 
offers  to  them  a  practicable  and  accurate  method  of  ascertaining  the 
actual  quantity  of  butter  fat  which  each  patron  furnishes  so  that  pay- 
ments may  be  based  not  on  volume  of  cream  supplied  but  on  actual 
butter  fat,  which  is  the  raw  material  that  the  creamery  manufactures. 
This  is  obviously  the  most  satisfactory  method  of  payment.  For  this 
purpose  each  patron's  cream  should  be  weighed  and  sampled  and  the 
fat  in  it  determined  by  the  method  described. 

Through  the  courtesy  of  the  managers  of  one  of  our  cream- 
eries it  is  now  proposed  to  study  the  practical  working  of  this 
method  in  a  creamery,  having  as  we  believe  assured  ourselves  of 
its  substantial  accuracy. 


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